This invention pertains to the art of electronic controlled engines and more specifically to providing an electrical input to an engine. The invention is particularly applicable to a new treadle assembly for an electronic system and will be described with reference thereto. However, it will be appreciated that the invention has broader applications and may be advantageously employed in related environments and applications.
Engine manufacturers have developed electronically controlled engines that are responsive to an electrical signal indicative of a driver's request for power. That is, the accelerator pedal or treadle assembly is located in the operator's or driver's compartment and when the treadle is depressed a suitable electronic signal is sent to an electrical control unit operatively associated with the engine. These assemblies typically include a potentiometer that generates an electronic signal corresponding to the amount of depression of the treadle. For example, systems of this type advantageously employ a rotary potentiometer mounted on the treadle so that the entire assembly can be located in the protected environment of the vehicle operator's compartment. An example of a commercially successful unit is shown and described in U.S. Pat. No. 4,528,590, the disclosure of which is commonly owned by the assignee of the present invention, and the details of which are incorporated herein by reference.
In addition to solving the problem of providing an electrical input to an electronic controlled engine, it is desirable that the arrangement also be of reduced size. The smaller sized assembly provides a wide array of options in mounting the assembly in the operator's compartment.
It is also desired to simplify the structure for maintenance and repair associated with the assembly. There is always an economic incentive to reduce the costs associated with maintenance and repair of the treadle assembly.
Many prior treadle assemblies are mounted on the floor where the components of the assembly are potentially exposed to high pressure wash, debris, mud, etc. Both the mechanical and the electrical components of the treadle assembly, such as the potentiometer, are susceptible to conditions in the vehicle operator compartment. Thus, although the vehicle operator compartment is a relatively protected mounting environment, compared to components mounted to the frame or in the engine compartment, floor mounted locations of the treadle assembly are less desirable for these additional reasons.